Friday, 6 January 2012

Article1:-Concept of Classes and Constructor with Example

Ans:- Class
is the way to realize real time entity in oops. It is the user defined data
type.

Syntax of
Class

public class
Class_Name

Note: public
is an access modifier which can be anything like public,private etc.

Ques:-2 What
is the Object?

Ans:-Object
is the Runtime Entity of the Class.

Syntax of
object Creation

Class_Name object_Name=new Class_Name()

Ques:3 What
is Constructor?

Ans:-Constructor
is the method inside the class which is used to initialize or give default
value to the class member variable. It is invoked when we create new instance
of the class.

Features
of Constructor

It has same
name as the name of the class

It is called
automatically when the instance of the class created.

It doesn’t have
any return type not even void

Syntax of
Constructor

Public class_name()

{

}

Example of Class,Object
and Constructor

In the
following example we are creating a class in which declare two variable of type
integer and a constructor which initialize these values with some hardcorded
value.

AppCode/Class1.cs

using
System;

using
System.Collections.Generic;

using
System.Linq;

using
System.Web;

publicclassClass1//Class Creation
Syntax

{

publicint x; //variable of class

publicint y;

public Class1() //construtor(on the name of the class)

{

x = 2; //initializing
the value

y = 3;

}

}

Default.aspx.cs

using
System;

using
System.Collections.Generic;

using
System.Linq;

using
System.Web;

using
System.Web.UI;

using
System.Web.UI.WebControls;

publicpartialclass_Default : System.Web.UI.Page

{

protectedvoid
Page_Load(object sender, EventArgs e)

{

Class1
cl = newClass1();//object creation

lblx.Text = cl.x;//calling the variable

lbly.Text = cl.y;

}

}

We create
the instance of the class1 cl. At the time of creating the class’s object the constructor
has called automatically and after that we show these class variable values in
the lables which shows the following output.